1. Field of the Invention
The present invention generally relates to a flywheel lock, and more particularly is concerned with an apparatus for locking a flywheel on an internal combustion engine so that ignition timing can be efficiently accomplished.
2. Description of the prior art
For proper engine operation and performance of a motorcycle engine, correct ignition timing and correct setting of the circuit breaker contact point gap is absolutely necessary. Therefore, it is essential to periodically check and reset ignition timing. This is generally accomplished by removing the engine circuit breaker cover and setting the circuit breaker contact gap at a setting prescribed by the engine manufacturer.
The first step in checking and adjusting ignition timing on a motorcycle is to correctly position the timing mark located on the engine flywheel. A generally accepted prior art practice first requires removing a screw plug from a bore that is located generally on the left side of the crank case. Removal of the screw plug exposes a timing inspection hole. The front push rod cover is then removed so that opening and closing of the engine valve can be observed. In order to position the timing mark located on the flywheel in the correct location, namely, within the inspection hole, the flywheel must be slowly rotated. This is accomplished by insuring that the front piston is on its compression stroke which occurs just after the front intake valve closes, continuing to slowly rotate the flywheel will bring the timing mark in correct alignment within the inspection hole.
However, certain disadvantages are implicit in this procedure. First, it is extremely difficult for one person to rotate a motorcycle flywheel while attempting at the same time to observe location of the timing mark on the flywheel and stop movement of the flywheel when the timing mark is observed within the inspection hole. Secondly, there is a certain amount of residual compression remaining within the engine that can cause the flywheel to move past the inspection hole. This movement will prevent the timing mark from remaining in position within the inspection hole.
One technique for positioning the timing mark within the inspection hole is to pry the flywheel into position by inserting a screw driver or some other type of long, blunt prying tool into the inspection hole. This technique can move the flywheel into position so that the timing mark is in the correct position. This practice can also cause damage to the internal threads on the bore wherein the inspection hole is located. In addition, this technique will not lock the flywheel in position so that residual compression in the engine can still cause the flywheel to move.
Consequently, a need exists for an apparatus that will result in greater reliability in locating an engine timing mark and then retaining the timing mark in correct position so that ignition timing can be effectively accomplished.